Structural Insights into the Stability and Recognition Mechanism of the Antiquinalphos Nanobody for the Detection of Quinalphos in Foods.

Nanobodies (Nbs) have great potential in immunoassays due to their exceptional physicochemical properties. With the immortal nature of Nbs and the ability to manipulate their structures using protein engineering, it will become increasingly valuable to understand what structural features of Nbs drive high stability, affinity, and selectivity. Here, we employed an anti-quinalphos Nb as a model to illustrate the structural basis of Nbs' distinctive physicochemical properties and the recognition mechanism.

Conformational adaptability determining antibody recognition to distomer: structure analysis of enantioselective antibody against chiral drug gatifloxacin.

Enantioselective antibodies have great potential to separate and detect chiral compounds. However, cross-reactivity of enantioselective antibodies to the distomer may limit the application. An in-depth understanding of interactions between antibodies and chiral drugs could be helpful to investigate antibody recognition to the distomer.

Two binding epitopes modulating specificity of immunoassay for β-agonist detection: Quantitative structure-activity relationship.

A growing number of β-agonists are illegally using for reducing animal fat deposition in animals, but the development of analytical methods always lags behind the emergence of new illegal compounds. Therefore, class specificity antibody-based immunoassays that can detect a great many β-agonists are important for timely supervision. In this study, a competitive inhibition enzyme-linked immunosorbent assay (ciELISA) based on a clenbuterol monoclonal antibody was developed to recognize 23 β-agonists and analogues.

Broad-specificity ELISA with a heterogeneous strategy for sensitive detection of microcystins and nodularin.

A highly sensitive and broadly specific competitive indirect enzyme-linked immunosorbent assay (ciELISA) method was developed for the simultaneous detection of nine microcystins (MCs) and nodularin (NOD) using MC-LR-keyhole limpet hemocyanin (KLH) for New Zealand white rabbit immunization to produce antibodies. The MC-LR-bovine serum albumin (BSA) and NOD-BSA coating antigens were compared and heterogeneous coating strategy was found to significantly improve the sensitivity of detection, as evident from the appropriate structure. Comparison of the half-maximum inhibitory concentration (IC50) with MC-LR and MC-LR-BSA coating techniques (0.

Four Hapten Spacer Sites Modulating Class Specificity: Nondirectional Multianalyte Immunoassay for 31 β-Agonists and Analogues.

Immunoassay methods are important for monitoring β-agonists illegally used for reducing animal fat deposition in livestock. However, there is no simultaneous screening surveillance immunoassay for detecting various β-agonist chemicals that are possibly present in food. In this study, through the use of an R-(-)-salbutamol derivative as the immunizing hapten, an antibody recognizing 31 β-agonists and analogues was generated for the first time.

Broad-Specificity Immunoassay for Simultaneous Detection of Ochratoxins A, B, and C in Millet and Maize.

Ochratoxins A, B, and C (OTA, OTB, and OTC) can be found in cereals and feeds; the simultaneous detection of these ochratoxins holds a great need in food safety. In this study, four antibodies raised from two ochrotoxin haptens and two coating antigens were compared, and then a sensitive and broad-specificity enzyme-linked immunosorbent assay (ELISA) was established for the simultaneous determination of three ochratoxins, where the detection limits were 0.005, 0.

Four Specific Hapten Conformations Dominating Antibody Specificity: Quantitative Structure-Activity Relationship Analysis for Quinolone Immunoassay.

Antibody-based immunoassay methods have been important tools for monitoring drug residues in animal foods. However, because of limited knowledge about the quantitative structure-activity relationships between a hapten and its resultant antibody specificity, antibody production with the desired specificity is still a huge challenge. In this study, the three-dimensional quantitative structure-activity relationship (3D QSAR) was analyzed in accordance with the cross-reactivity of quinolone drugs reacting with the antibody raised by pipemidic acid as the immunizing hapten and compared with the reported cross-reactivity data and their hapten structures.